I try to create an invite for an external user, using the graph API POST to https://graph.microsoft.com/v1.0/invitations
When the user has a + sign in his email-adres, the API responds with an BadRequest error. See attached screenshot. Whan I replace the + in the invitedUserEmailAddress with a - or _ the request works fine. An email-address with a + in the ccRecipients is accepted fine. According to the email-rfc's, a + sign is a valid character in the local part of an email-address.